Buggy code:
private Vector excludePackageNames = new Vector ( 1 ) ; private boolean author = true ; private boolean version = true ; private Javadoc . DocletInfo doclet = null ; private Path classpath = null ; private Path bootclasspath = null ; private String group = null ; private Vector compileList = new Vector ( 10 ) ; private String packageList = null ; private Vector links = new Vector ( 2 ) ; private Vector groups = new Vector ( 2 ) ; private boolean useDefaultExcludes = true ; private Javadoc . Html doctitle = null ; private Javadoc . Html header = null ; private Javadoc . Html footer = null ; private Javadoc . Html bottom = null ; private boolean useExternalFile = false ; private File tmpList = null ; private FileUtils fileUtils = FileUtils . newFileUtils ( ) ; public void setUseExternalFile ( boolean b ) { } public void setDefaultexcludes ( boolean useDefaultExcludes ) { } public void setMaxmemory ( String max ) { } public void setAdditionalparam ( String add ) { } public void setSourcepath ( Path src ) { } public Path createSourcepath ( ) { } public void setSourcepathRef ( Reference r ) { } public void setDestdir ( File dir ) { } public void setSourcefiles ( String src ) { } public void addSource ( Javadoc . SourceFile sf ) { } public void setPackagenames ( String src ) { } public void addPackage ( Javadoc . PackageName pn ) { } public void setExcludePackageNames ( String src ) { } public void addExcludePackage ( Javadoc . PackageName pn ) { } public void setOverview ( File f ) { } public void setPublic ( boolean b ) { } public void setProtected ( boolean b ) { } public void setPackage ( boolean b ) { } public void setPrivate ( boolean b ) { } public void setAccess ( Javadoc . AccessType at ) { } public void setDoclet ( String src ) { } public void setDocletPath ( Path src ) { } public void setDocletPathRef ( Reference r ) { } public Javadoc . DocletInfo createDoclet ( ) { } public void setOld ( boolean b ) { } public void setClasspath ( Path src ) { } public Path createClasspath ( ) { } public void setClasspathRef ( Reference r ) { } public void setBootclasspath ( Path src ) { } public Path createBootclasspath ( ) { } public void setBootClasspathRef ( Reference r ) { } public void setExtdirs ( String src ) { } public void setVerbose ( boolean b ) { } public void setLocale ( String src ) { } public void setEncoding ( String enc ) { } public void setVersion ( boolean src ) { } public void setUse ( boolean b ) { } public void setAuthor ( boolean src ) { } public void setSplitindex ( boolean b ) { } public void setWindowtitle ( String src ) { } public void setDoctitle ( String src ) { } public void addDoctitle ( Javadoc . Html text ) { } public void setHeader ( String src ) { } public void addHeader ( Javadoc . Html text ) { } public void setFooter ( String src ) { } public void addFooter ( Javadoc . Html text ) { } public void setBottom ( String src ) { } public void addBottom ( Javadoc . Html text ) { } public void setLinkoffline ( String src ) { } public void setGroup ( String src ) { } public void setLink ( String src ) { } public void setNodeprecated ( boolean b ) { } public void setNodeprecatedlist ( boolean b ) { } public void setNotree ( boolean b ) { } public void setNoindex ( boolean b ) { } public void setNohelp ( boolean b ) { } public void setNonavbar ( boolean b ) { } public void setSerialwarn ( boolean b ) { } public void setStylesheetfile ( File f ) { } public void setHelpfile ( File f ) { } public void setDocencoding ( String enc ) { } public void setPackageList ( String src ) { } public Javadoc . LinkArgument createLink ( ) { } public class LinkArgument { private String href ; private boolean offline = false ; private File packagelistLoc ; public LinkArgument ( ) { } public void setHref ( String hr ) { } public String getHref ( ) { } public void setPackagelistLoc ( File src ) { } public File getPackagelistLoc ( ) { } public void setOffline ( boolean offline ) { } public boolean isLinkOffline ( ) { } } public Javadoc . GroupArgument createGroup ( ) { } public class GroupArgument { private Javadoc . Html title ; private Vector packages = new Vector ( 3 ) ; public GroupArgument ( ) { } public void setTitle ( String src ) { } public void addTitle ( Javadoc . Html text ) { } public String getTitle ( ) { } public void setPackages ( String src ) { } public void addPackage ( Javadoc . PackageName pn ) { } public String getPackages ( ) { } } public void setCharset ( String src ) { } public void setFailonerror ( boolean b ) { } public void execute ( ) throws BuildException { } private void evaluatePackages ( Commandline toExecute , Path sourcePath , Vector packages , Vector excludePackages ) { } private class JavadocOutputStream extends LogOutputStream { JavadocOutputStream ( int level ) { } private String queuedLine = null ; protected void processLine ( String line , int messageLevel ) { } protected void logFlush ( ) { } } protected String expand ( String content ) { <START_BUG> return ProjectHelper . replaceProperties ( project , content ) ; <END_BUG> } private String getJavadocExecutableName ( ) { } }

Fix:
return project . replaceProperties ( content ) ;